Screening of Cowpea (Vigna unguiculata L. Walp) Genotypes for Rust (Uromyces phaseoli var. vignae) Resistance in Ghana
Theophilus Abonyi Mensah,
Sheila Matilda Ayorkor Tagoe,
Aaron Tettey Asare,
Daniel Sakyi Agyirifo
Issue:
Volume 6, Issue 4, December 2018
Pages:
67-74
Received:
26 November 2018
Accepted:
13 December 2018
Published:
10 January 2019
DOI:
10.11648/j.plant.20180604.11
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Abstract: The demand for cowpea (Vigna unguiculata L. Walp) is higher than supply in Ghana due to low yields caused by pathogenic diseases, predominantly rust disease. The use of rust resistant cultivars is the most effective method to control cowpea rust. Genetic variations among cowpea genotypes may be potential sources of rust resistance to control cowpea rust and increase cowpea yield and production in Ghana. The study assessed rust disease incidence and severity among cowpea genotypes and determined resistance to cowpea rust under field conditions. Twenty-four cowpea genotypes were sowed in four agro-ecological zones in two cropping seasons in Ghana. Cowpea rust incidence, severity, area under disease progress curve (AUDPC) and relative area under disease progress curve (rAUDPC) were significantly (p < 0.05) higher in the semi-deciduous forest and minor cropping season compared with deciduous forest, coastal savannah, Sudan savannah and major cropping season. The cowpea genotypes also showed significant differences (p < 0.05) in response to rust infection. Positive and negative correlations existed in rust incidence, severity, AUDPC and rAUDPC within the agro-ecological zones and cropping seasons. The differences observed were due to variations in climatic conditions and genetic composition of the cowpea genotypes. Five cowpea genotypes were better slow rusting, eleven cowpea genotypes were slow rusting and eight cowpea genotypes were fast rusting. Interestingly, eleven cowpea genotypes showed resistance and eight cowpea genotypes showed moderate resistance to cowpea rust. The rust resistant cowpea genotypes identified in this work can be recommended for farmers to cultivate and used in breeding programmes to further improve the crop. This will maximize yields and increase cowpea production particularly in rust prone areas.
Abstract: The demand for cowpea (Vigna unguiculata L. Walp) is higher than supply in Ghana due to low yields caused by pathogenic diseases, predominantly rust disease. The use of rust resistant cultivars is the most effective method to control cowpea rust. Genetic variations among cowpea genotypes may be potential sources of rust resistance to control cowpea...
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Response of Lentil Genotypes Under PEG-induced Drought Stress: Effect on Germination and Growth
Chrysanthi Foti,
Ebrahim Khah,
Ourania Pavli
Issue:
Volume 6, Issue 4, December 2018
Pages:
75-83
Received:
17 November 2018
Accepted:
5 December 2018
Published:
28 January 2019
DOI:
10.11648/j.plant.20180604.12
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Abstract: Drought has a negative impact on plant growth and is responsible for considerable crop yield loses worldwide. Given the importance of improving yield under drought, the ability to select tolerant genetic material is a prerequisite in all relevant plant breeding activities. Lentil is an economically important crop which often suffers from inadequate soil moisture. In this study, seed germination potential and seedling growth were determined in various genotypes exposed to drought as a means to explore the possibility of identifying drought-tolerant germplasm at an early stage. Drought stress experiments were carried out using six lentil cultivars, representing local and imported germplasm. Stress was induced by varying concentrations of polyethylene glycol (PEG6000: 0%, 5%, 10% and 20%). Genotype performance was assessed on a daily basis and referred to germination percentage (%), seed water absorbance (%), seedling water content (%), shoot and root length (cm) and number of seedlings with abnormal genotype. Our findings revealed that drought stress substantially affects parameters associated to germination and growth, with its effect being analogous to the stress level applied. Genotypic differences also were evident, with cultivars Elpida, Samos and Thessalia proving as the most tolerant and cultivar Flip 03-24L as the least tolerant genotypes under severe drought stress. Overall findings provide evidence that identifying drought tolerant germplasm might be accomplished by scoring seed germination and early growth potential under water deficit conditions. Such possibility is of outmost importance for a time- and cost-efficient selection of drought tolerant lentil genotypes to be exploited in breeding programs.
Abstract: Drought has a negative impact on plant growth and is responsible for considerable crop yield loses worldwide. Given the importance of improving yield under drought, the ability to select tolerant genetic material is a prerequisite in all relevant plant breeding activities. Lentil is an economically important crop which often suffers from inadequate...
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